1. Field of the Invention
This invention relates to well tools and more particularly to connectors for releasably connecting well tools together for performing downhole operations in wells, especially operations in which delicate instruments, or the like, are used and cannot be subjected to jarring impacts.
2. Description of the Related Art
It is well known to run well tools into wells on a flexible line to perform various downhole operations. Some operations require the use of electrically powered tools, and these tools are run into the well on an electrical conductor cable, electrical energy then being supplied to the downhole tool via the cable from a source of electrical energy on the surface.
Many downhole operations require the use of costly electrical powered instruments, such as electronic pressure transducers, electronic temperature transducers, or the like delicate instruments, either alone or in conjunction with other rather indelicate electrically powered downhole well tools.
Many downhole tools require jarring action in order to accomplish their function, but delicate and expensive instruments such as the aforementioned electronic pressure and/or temperature transducers, for instance, can be readily and severely damaged even by light jarring impacts. Such damage is costly in time, delay, and money, and may even render the downhole operation a complete failure.
Where such delicate instruments are to be used downhole in a well in conjunction with other well tools, especially where jarring will be necessary or likely, the operation of which would be hazardous to such delicate instruments, it is desirable to connect such delicate instruments to the other well tools with a releasable connector device which can withstand a straight upward pull of a predetermined value but which can be released by a straight upward pull of a predetermined lower value and without jarring the delicate electronic instruments. Such connector would make it possible to release the delicate instruments from the other well tools and withdraw them from the well, after which the cable (electrical cable, or non-conductor cable) would be run into the well and latched to the tools left downhole to allow further operations to be performed, including jarring, while the delicate instruments remain safe on the surface.
Connecting devices have generally been of the shear pin type or the spring-loaded type, either of which release in response to a straight upward pull of predetermined value. Some shear pin type connectors are designed to release upon shearing of the shear pin by jarring impacts.
The applicant is familiar with the following prior U.S. patents which disclose structures which may relate to the present invention. These prior patents are:
______________________________________ 2,698,056 3,215,208 3,452,777 4,321,965 2,884,071 3,227,462 3,664,427 4,407,362 3,100,533 3,273,649 4,252,143 4,583,592 3,102,593 3,278,192 4,252,195 4,625,799 3,183,972 3,395,728 4,274,485 ______________________________________
U.S. Pat. No. 2,884,071 which issued Apr. 28, 1959 to John V. Fredd shows a running tool releasably connected to the upper end of a well tubing plug by a simple and well-known shear pin. The shear pin is to be sheared by upward jarring impacts, but could be sheared by a straight upward pull of predetermined value.
U.S. Pat. No. 2,698,056 which issued to Samuel J. E. Marshall on Dec. 28, 1954 shows a running tool releasably connected to a well device with a pair of shearable pins which are disposed tangentially of the shearing surfaces.
U.S. Pat. No. 3,100,533 which issued Aug. 13, 1963 to John V. Fredd shows a running tool releasably connected to an anchoring and sealing device, this connection comprising a prong with an external recess latched into a first sleeve by balls carried in windows of this first sleeve for radial movement, and a second sleeve surrounding the first sleeve and confining the balls to their inner locking position. The prong is released when it is lifted sufficiently to allow the balls to move to an outer position and disengage the prong.
U.S. Pat. No. 3,102,593 which issued to Phillip S. Sizer on Sept. 3, 1963 shows a ball-sleeve connection very similar to that disclosed in U.S. Pat. No. 3,100,533, supra, but also shows lugs being used instead of balls.
U.S. Pat. No. 3,183,972 which issued to John V. Fredd on May 18, 1965 shows a running tool connected to a perforator hanger. This connection is similar to that seen in U.S. Pat. No. 3,100,533, supra, and it shows the running tool just having been freed in FIG. 2A.
Other well-known uses of balls, lugs, and collets are seen in the following patents:
U.S. Pat. No. 3,215,208 to Jack W. Tamplen, issued Nov. 2, 1965
U.S. Pat. No. 3,227,462 to Jack W. Tamplen, issued Jan. 4, 1966
U.S. Pat. No. 3,273,649 to Jack W. Tamplen, issued Sept. 20, 1966
U.S. Pat. No. 3,278,192 to Jack W. Tamplen, issued Oct. 11, 1966
U.S. Pat. No. 3,395,728 to Jack W. Tamplen, issued Aug. 6, 1968
U.S. Pat. No. 4,407,362 to Howard D. Bechthold, issued Oct. 4, 1983
U.S. Pat. No. 4,252,143 to John V. Fredd, issued Feb. 24, 1981
U.S. Pat. No. 4,252,195 to John V. Fredd, issued Feb. 24, 1981
U.S. Pat. No. 4,274,485 to John V. Fredd, issued June 23, 1981.
U.S. Pat. No. 4,321,965 which issued to Henry J. Restarick and John R. Setterberg on Mar. 30, 1982 teaches not only use of a well-known shear pin for emergency disconnect, but is primarily cited because it teaches use of a continuous zig-zag slot in which a pin carried by a rotatable sleeve travels as the slot is forced up and down relative to the pin to thus convert this longitudinal movement into rotational movement.
U.S. Pat. No. 4,625,799 which issued to William H. McCormick and Charles C. Cobb on Dec. 2, 1986 also shows a pin and continuous zig-zag slot arrangement for converting longitudinal movement into rotational movement. Thus, the nozzle section of a well washing apparatus is caused to rotate as a result of being lifted and lowered at the washing area.
U.S. Pat. No. 3,664,427 which issued on May 23, 1972 to Thomas M. Deaton discloses use of a continuous zig-zag control slot in a circulation control valve for use in wells. The control slot is formed in a collar carried on the stem of a valve biased toward its seat by a dome charge of gas. When dome pressure is overcome by external pressure, the valve moves off seat and the pin causes the collar to rotate. When external pressure decreases, the valve is latched open because the pin occupies a short leg of the slot. When pressures are cycled again, the pin reaches a long, open leg slot and the valve is allowed to close.
U.S. Pat. No. 4,583,592 issued to Imre I. Gazda on Apr. 22, 1986 and is cited here for two reasons. First, in the test tool device, as seen in FIG. 2A, a shear pin 272 releasably fastens sleeve 269 in place. Pin 272 can be sheared by an upward force on extension 236. O-ring 267 is placed between the lower end of sleeve 269 and upwardly facing shoulder on extension 236 to absorb shocks and thus prevent inadvertent shearing of pin 272. In actual public use, the connection seen in FIG. 2A was improved by placing additional o-rings above the sleeve so that slight downward jarring would be absorbed in the same way. That same shock absorbing connection is used on the present invention. Second, the device of FIGS. 1-8 is provided with a control slot 354 in which is engaged a control pin 350 carried on a floating (free to rotate) ring 348. As the slot moves up and down, the pin follows the slot and causes the ring to rotate. The control slot, as shown, on every fourth lift will cause lifting of a key release mechanism to unlock the test tool device from its landing receptacle. Otherwise, an upward pull will not release the lock mechanism, although a pull of a predetermined value (higher than the value of the pull otherwise required to unlock the device) will overcome the shear pin 272 and cause a disconnect at that point.
The present invention combines features like or similar to some of those found in the prior patents mentioned hereinabove and allows connecting costly and delicate electric or electronic instruments with other well tools in a tool string for running into a well to perform certain desired downhole operations and to gather certain desired well data, the data generally being gathered and the delicate instruments pulled from the well before jarring operations are commenced. Subsequently, a tool train including a connector device or fishing tool is lowered into the well, reconnected to the well tools left therein and operations continued. The present invention thus makes possible the safe use of delicate instruments in conjunction with other downhole well tools for accomplishing operations which otherwise would be risky, costly, impractical, or impossible.